BREMEN, GERMANY-The Bremen Institute for Metrology, Automation and Quality Science (BIMAQ) at the University of Bremen opened the Laboratory for large Gear Measurement on August 5, 2011.The facility is Germany's first university laboratory for the inspection of large gear wheels. The Bremen researchers can now measure toothed gear components from wind turbines. They can also investigate the interrelationships between design, manufacture, quality and functional characteristics of large gears and their effects on aspects such as wear, service life, types of defect and noise. The aim is to extend the life of large gearboxes in wind turbines.

At the heart of the Laboratory for large Gear Measurement is the Leitz PMM-F 30.20.7, a coordinate measuring machine (CMM) made by Hexagon Metrology, which is used for the inspection of the gear teeth on wind turbine components. This high-precision CMM is particularly suitable for measuring large parts. "With a measurement uncertainty of 1.3 +L/400 µm in the whole measurement volume of over 4 cubic metres, the Leitz PMM-F is one of the most accurate measuring machines of its class on the market," says Sebastian Haury, product manager Leitz at Hexagon Metrology. The measurement range is 3000 x 2000 x 700 millimeters. A 20-ton granite block ensures the structural strength and long-term stability of the measuring machine. At the same time, the machine shows a unique turn of speed, thanks to the typical Leitz principles behind its design. The Leitz PMM-F 30.20.7 is equipped with the QUINDOS 7 software package and can capture up to 750 measured points per second. Hexagon Metrology supplied the CMM as a turn-key system, complete with parts feed and air-conditioned measuring chamber.

The measuring machine had to be procured through an EU-wide tender. "Only one manufacturer was able to meet our high requirements," says BIMAQ Head, Prof. Dr.-Ing. Gert Goch. "Thanks to its high accuracy and especially its size, the Leitz coordinate measuring machine from Hexagon Metrology got the nod for this project. This coordinate measuring machine is the optimum solution for our research work, and we are also very pleased about the prospect of working with Hexagon Metrology in the future," says Goch. Before the new Leitz PMM-F arrived, BIMAQ was already using a Leitz Reference with a measurement range of 1000 x 700 x 600 millimeters. The Institute uses this CMM to research into the distortion of typical automotive gear wheel teeth.

A further aim of BIMAQ is to close the calibration chain for large components in the power train and gear-tooth cutting industries. "We would like to establish the laboratory as a certified testing authority for large gears," says Goch. "With the acquisition of the Leitz PMM-F, we have taken a great step forward in this direction. We are confidently looking forward to using this machine on many new projects, especially in the context of the rapidly growing economic importance of wind energy all over the world."